本科毕业论文-基于AT89S52单片机的智能机器人管家设计.docx

毕 业 论 文 评定成绩： 题 目 基于AT89S52单片机的智能机器人管家设计 性 质： 毕业论文 毕业设计学生姓名：班 级：电气13-1班系 别：机电工程系 专 业：电气自动化指导教师：黑龙江林业职业技术学院目 录封 面1 目 录.21摘要.34 2 正文511 2.1系统硬件电路的设计52.2核心控制单元AT89S52处理器.6 2.2.1 AT89S52单片机的主要性能6 2.2.2 AT89S52的功能特性描述62.2.3 AT89S52的引脚功能与封装.72.3 GSM数字移动通信模块782.4传感器采集模块.9 2.4.1温度传感器模块DS18B20.92.4.2DS18B20引脚及管脚功能介绍92.4.3烟雾传感器模块MQ-2气体传感器.102.4.4红外避障传感器模块.102.5 LCD1602液晶显示模块.113.结论124.参考文献135.谢辞14摘 要：随着电子技术的突飞猛进，单片机控制技术已渐渐渗透到电子技术、仪器仪表、自动控制等各个基础范畴。机器人是一个集环境感知、动态决定与规划、行为控制与执行等功能于一体的智能体，在智能控制及自动化控制系统中都有着广泛的使用。本文所要探究的是以单片机为核心的智能家庭自动化。智能家庭自动化，是当下最热门的科技话题之一。智能机器人管家就是其中的产物之一。本智能机器系统以单片机AT89S52作为核心控制模块，由GSM无线通信模块、传感器数据信息采集模块、液晶显示模块组成。通过传感器模块中烟雾传感器和温度传感器采集相关信号，经A/D转换模块转换成单片机可处理的数字信号，将该信号通过GSM短信模块，借助GSM移动网络，以中文短消息，直接把报警地点的情况反映到您的手机屏幕上。该系统安全保密性高，又不需要组建专用网络和维护网络，网络覆盖面广，因此与传统的监控系统相比有着其独特的优势。关键词：机器人管家，AT89S52单片机，GSM网络，传感器基于单片机的智能机器人管家设计Abstract: with the rapid development of electronic technology, SCM control technology has gradually penetrated into the electronic technology, instrumentation, automatic control and other basic areas. Robot is a set of environment perception, dynamic decision and planning, behavior control and execution, and other functions in one of the smart, intelligent control and automation control system has a wide range of use. This paper is to explore the core of the microcontroller as the core of the smart home automation. Smart home automation, is one of the most popular topics of science and technology. Intelligent robot steward is one of the products. The intelligent machine system takes SCM AT89S52 as the core control module, which is composed of GSM wireless communication module, sensor data acquisition module, LCD display module. Through the sensor module smoke sensor and temperature sensor acquisition related signals, through the A/D conversion module is converted into digital signal processing digital signal, the signal through the GSM SMS module, with GSM mobile network, the Chinese short message directly to the alarm location to your mobile phone screen. The system has a high security and privacy, and it does not need to set up the special network and maintenance network, the network coverage is wide, so it has its unique advantages compared with the traditional monitoring system.Keywords: robot housekeeper, AT89S52 microcontroller, GSM network, sensor2正文2.1系统硬件电路的设计本设计利用烟雾传感器、温度传感器先采集火灾情况，再将报警信息发送给单片机进行处理，然后，LCD液晶显示具体报警信息，由此可以知道具体报警位置及其类型。微处理器通过GSM模块以短信形式将特定报警信息发送于预先设定好的手机号码，通知事主信息。根据系统设计功能的要求，系统可分为4大模块：1)核心控制单元AT89S52模块；2)GSM无线通信模块；3)传感器数据信息采集模块4)液晶显示模块；系统原理框图如图所示 基于单片机的智能机器人管家设计2.2核心控制单元AT89S52处理器如今，AT89S52作为普通51单片机已广泛应用于各种产品中，其接口简单，方便使且功能强大，因此本系统采用AT89S52单片机作为主控制芯片。作为本设计的核心部分之一，由AT89S52担任的主控制器构成了系统的主控模块，它不仅用于设计的硬件实现，对于设计顺序的软件输入也起到控制作用，将控制整个机器人管家能否正常工作。2.2.1 AT89S52单片机的主要性能8K字节在系统可编程Flash存储器；电源工作范围在4.0V到5.5V；1000次擦写周期；全静态操作：0Hz33Hz；3级加密程序存储器；256字节内部RAM；32个可编程I/O口线；3个16位定时器/计数器；8个中断源全双工UART串行通道；低功耗空闲和掉电模式；掉电后中断可唤醒；看门狗定时器；双数据指针；灵活的在线编程（字节和页模式）；与各种MCS-51单片机兼容 。 2.2.2 AT89S52的功能特性描述AT89S52是一个低功耗，高性能CMOS8位单片机，片内含8kBytesISP(In-systemprogrammable)的可反复擦写1000次的Flash只读程序存储器，器件采用Atmel公司高密度、非易失性存储器技术制造，与工业80C51产品指令和引脚完全兼容。芯片内集成了通用8位中央处理器和ISPFlash存储单元，片上Flash允许程序存储器在系统可编程，亦适于常规编程器，功能强大的AT89S52可为许多控制应用系统提供高有的 解决方案。此外，AT89S52可通过软件设置省电模式。空闲模式下，CPU暂停工作，而RAM定时计数器，串行口，外中断系统可继续工作，掉电模式冻结振荡器而保存RAM的数据，单片机一切工作停止，直到下一个中断或硬件复位为止。停止芯片其他功能直至外中断激活或硬件复位。同时该芯片还具有PDIP、TQFP和PLCC等三种封装形式，以适应不同产品的需求。2.2.3 AT89S52的引脚功能与封装按照功能，AT89S52的引脚可分为主电源、外接晶体振荡或振荡器以及多功能I/O口控制和复位等。AT89S52的引脚排列如图 2.3 GSM数字移动通信模块GSM是欧洲邮电管理委员会(CEPT)下属的移动通信特别小组制定的通信协议。目前已建成的覆盖全国的GSM数字蜂窝移动通信网是我国公众通信网的主要方式。短消息服务(SMS)是通过移动网络用手机收发短消息的一种通信机制，SMS采用存储转发模式，短消息 发送以后，先要存储在短消息中心(SMC)，然后再由SMC将短消息转发给手机接收方。目前，国内已经开始使用的GSM模块有很多，而且这些模块的功能、用法差别不大。TC35是SIEMENS公司推出的新-代无线通信GSM模块，该模块支持GSM短信服务，具有功耗低、传输速度快、双频数据接口、集射频电路和基带于一体等特点并且大大缩小了用户产品的体积。设计选用GSM模块TC35i,给出其和PC机的通信电路，实现远程数据的传输。TC35i与GSM2/2兼容、双频（GSM900/GSM1800）、自带RS232数据通讯接口，可以方便地与PC机、单片机连机通讯。该模块及射频电路和基带与一体，向用户提供标准的AT命令接口，可以快速、安全、可靠地实现系统方案中的数据、语音传输、短消息服务(ShortMessageService)和传真，方便用户的应用开发及设计。该模块的外部接口包括天线接口、电源接口、串行总线接口及SIM卡插座。GSM模块通过异步通信接口实现对SMS的控制，接入协议一共有3种：BlockMode、基于AT命令的文本(TEXT)模式和基于AT命令的协议数据单元(protocoldataunit，PDU)模式。TC35模块的工作电压一般在3.35.5V,模块的供电电压如果低于3.3V则会自动关机,可以工作在900MHz和1800MHz两个频段,所在频段功耗分别为2W(900M)和1W(1800M)。模块有AT命令集接口,支持文本和PDU模式的短消息、第三组的二类传真、以及2.4K,4.8K,9.6K的非透明模式。此外,该模块还具有电话簿功能、多方通话以及漫游检测功能,为用户提供快速、可靠、安全的文本数据和语音数据的传输。常用工作模式有省电模式、IDLE、TALK等模式。通过独特的40引脚的ZIF连接器,实现电源连接、指令、数据、语音信号、及控制信号的双向传输。通过ZIF连接器及50天线连接器,可分别连接SIM卡支架和天线。向计算机串口发送AT命令操作TC35i模块的主要步骤如下(1) 利用OpenComm()函数初始化串口(2) 选择TC35iGSMMODEM的短信息服务功能(3) 选择短消息存储区(SIM卡/手机内存)(4) 选择接收或发送短消息的格式(TEXT格式/PDU格式)(5) 设置SIM卡的短信服务中心号码(6) 当所有准备就绪后才能发送短信息(一般发送一条短信）TC35模块主要有六部分组成，分别是：GSM基带处理器、GSM射频模块、供电模块(ASIC)、闪存、ZIF连接器、天线接口。作为TC35的核心,基带处理器主要处理GSM终端内的语音、数据信号,并涵盖了蜂窝射频设备中的所有的模拟和数字功能。在不需要额外硬件电路的前提下,可支持FR、HR和EFR语音信道编码。如图所示GSM模块中电源电路分为充电电池和稳压电源模块两部分：充电电池部分主要为整个系统提供3.6V的工作电压,同时产生MAX3238所需要的高电平；三端电源模块LM7806主要将外部12V直流电源转换为6V,连到ZIF连接器的11、12引脚,在充电模式下,为TC35i提供6V、500mA的充电电源。启动电路由开漏极三极管和上电复位电路组成。对模块上电10ms后(此时的电池电压须大于3V),为使之正常工作,必须在15脚加时长至少为100ms的低电平信号。启动后,15脚的信号应保持高电平。2.4传感器采集模块 传感器数据信息采集模块主要是采集外部信息：温度传感器及烟雾传感器是用来感测外界温度和烟雾的，若超过温度限制及检测到烟雾，则会产生火灾报警信息；再将这些信息传输到AT89S52单片机控制模块，以进行后面的报警操作。 2.4.1温度传感器模块DS18B20以及其特点（1）单线结构，只需一根信号线和CPU相连（2） 不需要外部元件，直接输出串行数据。（3）温度数字量转换时间200ms（典型值）。（4）可不需要外部电源，直接通过信号线供电，电源电压范围为3.3V5V。（5） 测温精度高，测温范围为：-55+125，在-10+85范围内，精度为0.5。（6）具有非易失性上、下限报警设定的功能，用户可方便地通过编程修改上、下限的数值。2.4.2DS18B20引脚及管脚功能介绍DS18B20的常用封装有3脚、8脚、16脚等几种形式。各引脚功能如下：DQ：数字信号输入/输出端。GND：电源地端。VDD：外接供电电源输入端。DS18B20内部结构简要介绍：DS18B20的内部结构主要有64位光刻ROM、温度传感器、非易失性温度报警触发器TH和TL、配置寄存器等组成。64位光刻ROM是生产厂家给每一个出厂的DS18820命名的产品序列号，可以看作为该器件的地址序列号。其作用是使每一个出厂的DS18820地址序列号都各不相同，这样，就可以实现一根总线上挂接多个DS18820的目的。DS18B20中的温度传感器完成对温度的测量，输出格式为：16位符号扩展的二进制补码。当测温精度设置为12位时，分辨率为0.0625，即0.0625/LSB。其中，S为符号位，S=1，表示温度为负值；S=0，表示温度为正值。例如+125的数字输出为07D0H，-55的数字输出为FC90H。DS18B20中的低温触发器TL、高温触发器TH，用于设置低温、高温的报警数值。DS18B20完成一个周期的温度测量后，将测得的温度值和TL、TH相比较，如果小于TL，或大于TH，则表示温度越限，将该器件内的告警标志位置位，并对主机发出的告警搜索命令做出响应。需要修改上、下限温度值时，只需使用一个功能命令即可对TL、TH写入，十分方便。DS18B20中的高速暂存器是一个9字节的存储器。开始两个字节为被测温度的数字量，第3、4、5字节分别为TH、TL、配置寄存器的复制，每一次上电复位时被重写。配置寄存器有R0、R1组成，其值决定温度转换的精度位数、转换时间等。第7字节为测温计数的剩余值。第8字节为测温时每度的计数值。第9字节读出的是前8个字节的CRC校验码，通过此码，可判断通讯是否正确。2.4.3烟雾传感器模块MQ-2气体传感器MQ-2烟雾传感器，在可燃气体或烟雾中MQ-2烟雾传感器的电阻会有相应的变化。MQ-2气敏元件由微型AL2O3陶瓷管、SnO2敏感层,测量电极和加热器构成的敏感元件固定在塑料或不锈钢制成的腔体内，加热器为气敏元件提供了必要的工作条件。封装好的气敏元件有6只针状管脚，其中4个用于信号取出，2个用于提供加热电流。MQ-2气体传感器的优点：灵敏度高，性能稳定，对烟雾固体小颗粒灵敏度高，价格较低。而且驱动电路简单。MQ-2气体传感器的缺点：管脚较多有6个，需要电流提前加热功能才更好。结构如图所示2.4.4红外避障传感器模块红外避障传感器/距离可调3-80cm，这是一种集发射与接收于一体的光电传感器。检测距离可以根据要求进行调节。该传感器具有探测距离远、受可见光干扰小、价格便宜、易于装配、使用方便等特点，可以广泛应用于机器人避障、流水线计件等众多场合。避障传感器的工作原理，和循迹传感器工作原理基本相同，利用物体的反射性质。在一定范围内，如果没有障碍物，发射出去的红外线，因为传播距离越远而逐渐减弱，最后消失。反之，如果有障碍物，红外线遇到障碍物，被反射到达传感器接收头。传感器检测到这一信号，就可以确认正前方有障碍物，并送给单片机，单片机进行一系列的处理分析，协调机器人管家的两轮工作，完成一个漂亮的躲避障碍物动作。2.5 LCD1602液晶显示模块LCD1602液晶显示器模块，有微功耗、体积小、显示内容丰富、超薄轻巧等诸多优点，最大程度上的方便大家，使得该系统更加人性化。且LCD1602液晶显示器在袖珍式仪表和低功耗应用系统中得到越来越广泛的应用。故采用LCD1602液晶显示器。LCD1602的主要技术参数如下图根据显示的容量可以分为1行16个字、2行16个字、2行20个字等字符图形，这些字符有：阿拉伯数字、英文字母的大小写、常用的符号、和日文假名等，每一个字符都有一个固定的代码，比如大写的英文字母“A”的代码是01000001B（41H），显示时模块把地址41H中的点阵字符图形显示出来，我们就能看到字母“A”。LCD1602的主要功能：1.40通道点阵LCD驱动;2.可选择当作行驱动或列驱动3.输入/输出信号:输出,能产生202个LCD驱动波形;输入,接受控制器送出的串行数据和控制信号,偏压(V1V6)4. 通过单片机控制将所测的频率信号读数显示出来主程序图如下基于单片机的智能机器人管家设计3.结论本设计借助最可靠、最成熟的GSM移动网络，以最直观的中文短信息形式，直接把报警信息反映到当事人的手机上。当家中出现紧急信息时，安装在小车上的相应部位的传感器马上就能检测到，并且立即把信号传送到控制中心，经过一系列信号转化后，转换后的信号通过GSM网络传送到当事人的手机上，即是先把信息送到SMS服务平台，而后通过基站传送出去。整个传送过程只需几秒种的时间，能够准确地通知家中被检测出了问题，以便于当事人能够及时的采取补救措施。首先，硬件部分我们从五个模块着手，首先是通过传感器模块采集到家中的紧急信息，将信息传到微处理器上，由核心控制模块AT89S52单片机，转而控制液晶显示模块，这样，发出报警短信，再通过GSM模块以实现远程监控功能，将报警信息发送到当事人手机上，保证当事人能够及时根据报警信息进行抢救。其次，软件部分在对芯片的管脚功能和用法以及整个GSM网络有充分的了解后，根据设计要求设计了硬件电路，包括传感器采集信息电路、单片机控制电路、GSM模块连接电路，然后再编写所需要的程序，再通过软件编程，实现了对家庭系统的远程监控和报警功能，这样，基本实现了预期的目标。参考文献：1. 唐桃波,陈玉林基于AT89C52的智能无线安防报警器.电子设计应用,20032. 齐国光,郭木河等.轮式机器人最优控制的研究.机器人,19963. 津川.智能自动车的控制方法和计算机系统.机械技术研究所报,19504. 鲁昌华基于GSM无线防盗报警系统的研制J电子测量与仪器学报5. 胡学海.单片机原理及应用系统设计M.北京:电子工业出版社6. 沙占友.智能传感器系统设计与应用M.北京:电子工业出版社谢辞光阴似箭，为期三年的林校学习生涯即将结束。同时，经过努力，我的毕业论文也完成了。本次论文的撰写，对我而言是一次难得的锻炼机会。在敲完最后一个句号的时刻，我的思想同周围凝固的热气一样停驻了，不知道是慰藉还是悲伤，大学三年的生活就这样结束了，而眼前的路还很长，虽然似乎有些迷茫，但我必须整理心情，背上行囊，坚定的踏上新的征程。首先我要感谢我的指导老师的大力帮助和支持。本论文能够顺利完成，离不开李老师的悉心指导和严格要求，李老师在论文的选题、研究理论、框架结构、数据整理，直至撰写、修改和定稿等各个环节均严格把关，并投入了大量的时间和精力。李老师治学严谨，学识渊博，为我营造了一种良好的研究氛围。在跟随李老师学习的过程中，我不仅掌握了全新而实用的学术思想和研究方法，也领会了许多待人接物与为人处世的道理。李老师严以律己、宽以待人的崇高风范，朴实无华、平易近人的人格魅力，令人如沐春风，倍感温馨。其次，我要衷心感谢我们的导员慈老师，为我们班的无私奉献，陪伴我们成长。感谢我的同学们，四年的相处将成为我美好的记忆。感谢我的舍友们，感谢她们在我的学习和生活上对我的关爱与包容。当然，我还要感谢我的母校黑龙江林业职业技术学院，在校期间，这里给我留下了美好的回忆。感谢我们的学院机电工程学院，为我们提供了良好的做毕业设计的环境，特别是在我即将继续深造的时候，毕业设计整个过程给了我这样一个锻炼的机会，使我加深了对以前知识的理解和巩固，拓宽了知识面，也提高了我对所学知识的综合应用能力。我要对母校说：今天我以母校为骄傲，明天母校以我为骄傲。祝愿母校的将来更美好！最后在这里我想向所有帮助过我，鼓励过我的人们致以最诚挚的谢意，感谢你们在人生最关键的时刻给予我的指引！我将满怀憧憬和希望，沿着我的理想之路继续前进！您好，为你提供优秀的毕业论文参考资料，请您删除以下内容，O(_)O谢谢！A large group of tea merchants on camels and horses from Northwest Chinas Shaanxi province pass through a stop on the ancient Silk Road, Gansus Zhangye city during their journey to Kazakhstan, May 5, 2015. The caravan, consisting of more than 100 camels, three horse-drawn carriages and four support vehicles, started the trip from Jingyang county in Shaanxi on Sept 19, 2014. It will pass through Gansu province and Xinjiang Uygur autonomous region, and finally arrive in Almaty, formerly known as Alma-Ata, the largest city in Kazakhstan, and Dungan in Zhambyl province. The trip will cover about 15,000 kilometers and take the caravan more than one year to complete. The caravan is expected to return to Jingyang in March 2016. Then they will come back, carrying specialty products from Kazakhstan A small art troupe founded six decades ago has grown into a household name in the Inner Mongolia autonomous region. In the 1950s, Ulan Muqir Art Troupe was created by nine young musicians, who toured remote villages on horses and performed traditional Mongolian music and dances for nomadic families. The 54-year-old was born in Tongliao, in eastern Inner Mongolia and joined the troupe in 1975.He says there are 74 branch troupes across Inner Mongolia and actors give around 100 shows every year to local nomadic people. I can still recall the days when I toured with the troupe in the early 80s. We sat on the back of pickup trucks for hours. The sky was blue, and we couldnt help but sing the folk songs, Nasun says. The vastness of Inner Mongolia and the lack of entertainment options for people living there, made their lives lonely. The nomadic people were very excited about our visits, Nasun recalls. We didnt have a formal stage. The audience just sat on the grass. Usually, the performances became a big party with local people joining in. For him, the rewarding part about touring isnt just about sharing art with nomadic families but also about gaining inspiration for the music and dance. Ulan Muqir literally translates as red burgeon, and todays performers of the troupe still tour the regions villages and entertain nomadic families, but their fame has spread around the world. On May 16 and 17, nearly 100 singers and dancers from the troupe performed at Beijings Poly Theater. Their show, titled Ulan Muqir on the Grassland, depicted the history and development of the art troupe. Being from the region allowed me to embrace the culture of Inner Mongolia and being a member of the troupe showed me where I belonged, Nasun, the art troupes president, who is also a renowned tenor, tells China Daily. During a tour in 1985, he went to a village and met an elderly local man, who told him a story about his friendship with a solider from Shenyang, capital of Northeast Chinas Liaoning province, decades ago. The solider gave the old man a handmade saddle when they bid farewell. The story inspired Nasun to write Carved Saddle, a song that later became one of his most popular numbers. Now, every year, Nasun recruits young singers and dancers for the troupe. The troupe has also designed a new repertoire, which is mostly based on the daily lives of Mongolian people, especially the lives of nomadic families, and has combined contemporary musical elements with folk songs of the region. Haimu, a 25-year-old khoomei (a local variant of overtone singing) singer, joined the troupe three years ago. Along with a six-member band, he performs fast songs and soft ones that he writesall while playing the horse-head fiddle.Although I learned the piano since childhood and grew up listening to various kinds of music, to me, the folk music of Inner Mongolia is the root, he says. Performing in remote villages is pleasant. I feel at home on the boundless grasslands, and the warm people there make me feel fulfilled. The first round of spring auction season in Beijing ended last week, but it failed to create much spring in the art market. Although two pieces of Chinese painting fetched more than 100 million yuan, the decline in trading volume and sale rate showed a downturn this year. In the “Grand View: Chinese Painting Highlight” session at China Guardian 2015 spring auctions, Pan Tianshous representative work Eagle, Rock and Flora hit a record auction price of 279 million yuan, while Li Kerans masterwork Jinggang Mountain fetched 126.5 million yuan, an unexpected high in recent years. However, the trading volume fells to 1.87 billion yuan from 2.22 billion yuan in the same period the year before. The Huangchen 2015 Spring Auctions, which recorded 42.5 million yuan in total sales, experienced the same. The section number went down to 5 from 12 compared to last year. According to expert Shao Jianwu, the art market did not attract much excitement this year due to the booming stock market and the persistent problems of forgery and fake deals. The two pieces of Chinese painting notched up high price this spring due to their own value not due to a revival in the market. The successful transaction of two works with a hammer price of more than 100 million yuan once again confirms that valuable and rare works of high quality always earn the long-lasting high price. Chinese painting and calligraphy is still the pillar of the market. However, the overall sales rate has dropped slightly, which reflects the demand for the ordinary auction goods has weakened,” said the president of China Guardians Hu Yanyan. Besides, the entry of new buyers also makes certain changes to the direction of purchasing. In a word, the overall market trend is very unpredictable. Although China Guardian 2015 Spring Auctions has achieved remarkable results, it does not mean that the market has walked out of the predicament. We still have to wait for the big economic boom to invigorate the art market.” Even so, the hot pursuit of some special items appeared this spring. A special session of China Guardian Spring Auctions titled “Fine GiltBronze Buddhist Images” achieved a great deal with total sales volume of 41.89 million yuan and 92 percent sale rate. The 5th Shamar Rinpoche Statue from 16-17th century of Tibet was sold for 5.06 million yuan. The Beijing Chengxuan Auctions featured almost 2,800 items of coins and stamps in three sessions with good sale rate. The Huachen Auctions also set a special session of photographs under the condition of large-scale decline of auction sessions. There was a palpable dull thud of disappointment that accompanied the return of the imperial entourage of Zhen Huan to her homeland. It followed a couple years of hushed excitement as Chinese fans were fed tidbits about their proud concubine who was supposed to conquer the high ground of the North American market. Zhen Huan is, of course, the title character of The Legend of Zhen Huan, a 2011 television series that swept China off its feet and later took other Asian countries by storm. Two years ago, it was reported that HBO, a premium cable service headquartered in the United States, was going to air it in North America after some modification. Now, a condensed version that provides English subtitles but no dubbing has finally been made available on Netflix for online streaming. This version, highly anticipated as a milestone in Chinas cultural foray overseas, has been widely panned by its home audience. Retitled Empresses in the Palace, the American version has been shortened from its original 76 episodes at 45 minutes each, to six 90-minute episodes. The quick pacing threw off many native viewers, who are accustomed to a more leisurely daytime-soap-style narrative rhythm. (Chinese TV stations would run two or three episodes every day.) I did not finish the full-length version and found the truncated one not difficult to follow. Whats lost, I believe, are the interesting setups and pauses that illuminate the Chinese art of storytelling. Much of the plot is still there. It is the flavor that was sacrificed. The American edition uses the framework of the Empress Dowager in her senior years reminiscing at the beginning and the end of each episode, hinting at whats to come and recapping the key points. This device, not used in the original, is culturally understandable but artistically mediocre. What puzzles me is the two new songs for the opening and end credits. They were written in English, but sung by Chi